In recent years, to reduce the burden imposed on a driver, a device has been developed which provides various kinds of driving assist to the driver. In an ACC [Adaptive Cruise Control] device which enables automatic acceleration/deceleration control of a vehicle, when there is a preceding vehicle, acceleration/deceleration control is performed such that an appropriate inter-vehicle distance (time) from the vehicle to the preceding vehicle is maintained, and when there is no preceding vehicle, acceleration/deceleration control is performed such that a set vehicle speed is maintained. Meanwhile, to perform acceleration/deceleration according to a manual operation of a driver, for example, Patent Citation 1 describes a method which searches a requested torque map in accordance with the opening degree of an accelerator by the driver to obtain the requested torque, when it is determined from a comparison of the current requested torque with a requested torque after smoothing that it is an acceleration state, calculates an acceleration assist amount in accordance with the difference between the current requested torque and the requested torque after smoothing, and adds the acceleration assist amount to the requested torque after smoothing to set a target torque.    [Patent Citation 1] Japanese Unexamined Patent Application Publication No. 2001-73839    [Patent Citation 2] Japanese Unexamined Patent Application Publication No. 2006-42528    [Patent Citation 3] Japanese Unexamined Patent Application Publication No. 2001-238306    [Patent Citation 4] Japanese Unexamined Patent Application Publication No. 2004-50904